Circuit breaker



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Patented Sept. 14, 1948 Anarran 4.sunurses .fornisca f CIRCUIT BREAKRlErnstiEicheiilcergerf- Wettingen 'Sttze'rlad,`-'asffvsignorf tol-Ak'tien'gesellsch'alf Application' January; 16, 1946fSerial"NoI..6`41"I571 `I Switzerland J anu'ary'i26,"1945 vThis l'inventionrelates in @general :.to'-circuit breakersand in particularto circuiti;breakers constructed for use in interruptingdireot'. current powerloads.

Generally speakingfarcs '.iormed by` separation of Ithe 'contact''elements or circuit'. breakers .ofconventional design wheninterruptingadirect current load are extinguished by extending the length rvof`the'arc untilthe voltage requiredto maintain it is; greater' than vtheline voltage., of .the directcurrent 'systeminwhich thecircuit breakerisf connected. Various.:.expedientshave been devised .foraccomplishing-this. In one arrangement, `,the circuitbreakers.` havebeen vprovided withwalls of` metal or insulating material which arevpositionedftransversely. of .the arc path, so that the arc canapplynitself. in wave form .tothe edgesof .thesefwalls .The extension ofthe'loop pcrtionof the arc betweensuch walls'kk has also been aided bytheusey ofr pressure gasin order to improve yits l extinguishingcharacteristic. Furthermore, iti has also been proposed"to"arrangemetalparts in an arc extinguishingr chamber of insulating material so-that Vthese "parts are touched bythe "loops of the`V arc -wnerebyheatis e'xtracted'from the 4arc' andiits extinguishing facilitated.

For use on alternating current circuits; 'circuit breakers have been'disclosedwhichfcomprise at least'- one hollow, nozzlercontactthroughwhich .the

are, formed uponseparation of the circuit breaker contacts,-is-'blownfwith pressuregas. *Such constructionv is quite-satisfactoryVfor breaking." alternating current loads. Since thearcrln `the'hollowcontact --isl surrounded `Aon alli sides vwith' the? gas streamlan'dcooled' downf greatly, L andialso` since the space -between the contacts'is rapidly deionized by the flowing gas, theiarc is: extinguished asthe current wave-passes through. zero .and will not reestablish itself.

' Circuit-breakers of the lattertype',.howeveiare not suitable for! usef in interruptingdirect current loads because, in a direct currentsystem, theamplitude of the current? and. voltage Visrmaintained atsloadvalues and' hencer doesznot possess a, .zero characteristic as inalternating.; current systems.

Arr object of thislfinventionis to providea novel and improvedcircuitbreaker construction for use on circuitswhich carry direct'current' loads. `.In a preferred formffmy improved circuit..y breakerincludes'a pair of contact e1ements,'ronezof which is hollow,` and the;other-being 4,in the shape, of; a pin` havinglaniendportiorrwhichfenters5 and nor- :r1-'allyv rests? against :thelower-wendfofr the hollow contact-tdrclose a "circuit therethrough.v-:lnei ytwoi contactelements are mounted sothat oneofthemseparatesffrom the other whensubjected to a blast of' gasunder-pressure- An arc blowingrchamber `adj oins thehollowcontact andthe sidewall thereofr supports a"-plurality-of-metal pins whicharearranged vertically'oneabove the other. One of thecircuit"breaker'contacts has 'connected to it amaro-receivingeleotrodewhich extendsinto the lower end of the blowing" chamber. Uponseparation vofthe' circuitbreak'ercontacts, one root of the'arc4 formedthereby f ascends thisarc-'receiving electrode and thefother'rootof thearc is hel'd`by`the 'ther circuit breaker contact. The medial portion ofthe arc loop is blown up through theiarcblowingchaniber;climbingupwardly from pin *to pinf and thusfleng'theninguntil' extinction takes place.

'In the''drawingsf--wliichillustrate preferred embodimentsof'theinvention Fig, l is a vertical section"showing1 a constructionwherein twol circuit breaker sections each embodying the invention areconnectedlin series. flig.M la is av transversefsection taken'fonlineIct-#Ia ofliig. l. Fig. 2y alsok al verticalfsection -showsvvv` anotherarrangeirientfwherein` Va single gas conduit is used to feed gas to; thecontact/i vsets off both "circuitbreaker sections.

*Referring-'nowi-to Fig. l ofthe drawing, atank I having aflattop'surface isf'provided, and. is adapted-'tc receive gasunderpr'essure from pipe 2 and to supply the'- pressure fg'as' to thecircuit through a control valve 3. Twoicircuit'breaker sectionsldand-idf embodying thelinvention are supported by tank .I.

Circ:uitibreaker-Lsection` #includes annular casing sections 6' andA IIseparated by anannulariinsulating columna-to constitute a' contactchamber 9. v.Thelower section I is bowl-'shaped and thebottom'thereofterminates in a ilange Il] which restsnupon':anlannulareinsulator I I, lthe latter being supported upon and'incommunication with theiinterior tif-:tank Ilkthrough the valve 3. Oneside of fthedirectfr currentc'ircuit to be broken isconnectedatfterminal .I 2 to thev lower :section l.

.;'Ihecontact structure of .circuit breakerl section4,1'which'ish'ousedwithin chamber 9 includes a hollowl Contact'.`element I3 which may be cylindri'cal,` 'as snown,ortapered. outwardlyfrom the bottom,"anda pintype.contactelement I4 cooperating therewith.The middle-portion vl5 of pin I4 .hasa ,diametery slightly.'largerI thanthe inside diameter of the opening .through hollow contact elementzl thebottom 'portion iii-of the pin contact 'I 4=is taperedland .i-hefnpperportion I 'I `thereofoissharr'edf-to rod'iform ofafcornparatively smalldiameter to constitute an arc-receiving electrode of the circuitbreaker.

Pin I4 is iixed in position by means of supporting ribs I8 which extendupwardly from the lower section 1 of contact chamber 9.

Contact element I3 is provided with a ilange 20 at the bottom thereof.The upper section 6 of contact chamber 9 also carries an internal flange2I. A coil spring 22 inserted between the two flanges 20 and 2I urgesthe lower end of hollow contact element i3 into engagement with theenlarged medial portion I of contact pin I4.

Adjacent the upper or outlet side of the hollow contact I3 is a. tubularhousing 23 which may be cylindrical, as shown, or tapered outwardly fromthe bottom up, if desired. Housing 23 is made from insulating materialand forms an arc blowing chamber for the arc. A plurality of pins 24 ofconductive material are arranged in vertically spaced relation inside ofthe housing and are supported in the wall thereof, it being noted thatthese pins project through the wall on both sides.

Surrounding tubular housing 23 is another tubular housing 25 also ofinsulation material which is supported within an annular groove 26formed at the top of the upper contact chamber portion 6. Supported by,and projecting through, the wall of housing 25 are a plurality ofauxiliary pins 21 spaced vertically, there being a pin paired with andat the same level as each of the pins 24.

A metallic cap member or mufer 28 extends across the top of housings 23and 25.

The component parts of the circuit breaker section 4' are constructedand arranged in the same manner as corresponding parts of circuitbreaker section 4. Accordingly, corresponding parts of the two circuitbreaker sections have been designated by corresponding referencenumerals, but with primes added thereto, and no further description ofcircuit breaker section 4' is deemed necessary.

The two circuit breaker sections 4 and 4' are electrically connected inseries. Hence metallic caps 28 and 23 are interconnected by conductor39; corresponding sets of auxiliary pins 21 and 21' are interconnectedby conductors 3 I; and the upper contact chamber sections 6, 6 areinterconnected by conductor 32. The other side of the line adapted to bebroken by the circuit breakers 4 and 4' is connected to terminal I2' onthe lower control chamber section 1 of circuit breaker section 4.

Operation of the two circuit breaker sections 4 and 4 shown in Fig. 1 isstarted by opening valves 3, and 3 which permit gas under pressure toflow up through the insulator sections I I, I I' into the contactchambers 9 and 9. Here the gas pressure is applied to the undersides ofthe ilanges 20, 2G' on hollow contact elements I3 and I3', causing thelatter to be lifted upwardly against the action of springs 22, 22 tobreak the electrical contact between the pins I4, I4' and their matedhollow contacts I3, I3'. The arcs formed at the two circuit breakingpoints are blown up through the hollow contacts I3, I3 under the actionof the pressure gas and then extended to form arc loops. One end of eachof the arc loops travels upwardly to the top of the electrodes I1, I1'which terminate inside of the housings 23, 23', and these end portionsof the arcs are bathed on all sides by the pressure gas stream whichforces the arcs into the blowing chambers.

The other end portions of the respective arcs are blown into thehousings 25, 25', and are there extended upwardly to bring the medialportions o! the arc loops across the gap between the opposed ends of thelowermost sets of pins 24, 2l and 24', 21', respectively. Portions ofthe arc loops are thereby short-circuited and extinguished; and the arcloops are similarly transferred upwardly to succeeding sets of pins 24,21 and 24', 21 by the pressure gas blast.

When current is eventually interrupted by the stretching of the arcswhich spring from electrodes I1, I1', reignition is effectivelyprevented as the ilow of pressure gas has completely deionized thespaces between the respective sets of circuit breaker contacts I3, I4and I3', I4.

A modified construction of a circuit breaker incorporating the inventionis shown in Fig. 2. Here both circuit breaker sections 4a and 4b have acommon contact housing, the lower bowl-like portion 1a of which issupported upon a single tubular insulator IIa that is in turn supportedupon the tank Ia. The lower portion of the contact housing divides intotwo chambers 9a and 9b which include hollow contacts I3a, I3b and matingcontact pins I4a, I4b.

The electrodes Ila and I1b of contact pins, Ilia, I4b differ from theconstruction used in Fig. l in that the electrodes I1a, Ilb terminatewithin and just below the top of the hollow contacts I3a, 13b.

In the Fig. 2 arrangement, additional arc-receiving electrodes 34a, 34hare supported upon the hollow contacts I3a, |312 and these electrodesare extended to a point within the arc blowing chambers formed byhousings 23a, 23h. The line terminals I2a, I2b are carried by thehousings 6a, 6b in this form of the invention. Operation of the circuitbreakers shown in Fig. 2 is substantially the same as that of Fig. 1.

If desired, only one of the circuit breaker sections such as the sectionon the left in Fig. 1 need be utilized to interrupt a direct currentload in which case the projections 21 must be interconnected amongthemselves and to the contact I3; however, connection of two circuitbreaker sections in series is advantageous in that it breaks the arc gapinto a greater number of sections which are more easily extinguished.

I claim:

1. In a pressure gas circuit breaker for interrupting a direct currentload, a pair of contact elements, one of said elements being hollow,means supporting said contact elements for movement of at least onecontact relative to the other to open a circuit therebetween under theaction of pressure gas, an inner tubular casing of insulating materialconstituting an arc blowing chamber, the bottom of said casing beingopen 'and disposed adjacent said hollow contact, an arc-receivingelectrode connected to at least one of said contact elements, saidelectrode being extended into the lower portion of said casing, aplurality of conductive pins spaced one above the other and extendingthrough the wall of said casing, an outer tubular casing of insulatingmaterial surrounding said inner casing and through which pressure gasiiows, and at least one arc attracting electrode located in the spacebetween said inner and outer casings and carrying the potential of theother of said contact elements.

2. A circuit breaker as dened in claim 1 wherein a plurality of arcattracting electrodes are located in the space between 'the inner andouter casings, said electrodes being constituted by conductive pinssecured in the wal1of the outer casing, said pins being electricallyconnected with,

each other and with the other of said contact elements.

3. A circuit breaker as defined in claim 1 characterized by the featurethat said casing is cylindrical.

4. A `circuit breaker as deiined in claim 1 characterized by the featurethat said supporting means for said contact elements include a springnormally urging said elements into engagement with each other but whichis yieldable under the action of pressure gas to permit separation ofsaid elements.

5. In a pressure gas operated circuit breaker system for use ininterrupting direct current loads; a pair of circuit breakers; each saidcircuit breaker including a pair of contact elements, one of saidelements being hollow, means Supporting said contact elements formovement of one relative to the other under the action of gas pressureto open a circuit therebetween, an inner tubular casing of insulatingmaterial constituting an arc blowing chamber, the bottom of said casingbeing open and disposed adjacent said hollow contact element, anarc-receiving electrode connected to at least one of said contactelements, said electrode being extended into the lower portion of saidcasing, a plurality of metal pins, said pins being spaced one above theother in the wall of said casing, an outer tubular casing of insulatingmaterial surrounding said inner casing and through which pressure gasflows, and a plurality of vertically spaced pins extending through theWall of said outer casing; means connecting corresponding pins in thewalls of the outer casings of the two circuit breakers; means connectingsaid breakers electrically in series; and means for actuating thecontact elements of both said breakers simultaneously.

6. A circuit breaker system as defined in claim 5 and further includingseparate tubular insulator means for supporting each said circuitbreaker, the interior of each said insulator means being incommunication with the contact elements of its respectively associatedcircuit breaker and adapted to pass pressure gas therethrough to saidcontact elements.

'7. A circuit breaker as defined in claim 5 and further including 'asingle tubular insulator supporting both said circuit breakers, theinterior of said insulator beingr in communication with the contactelements of both said circuit breakers to pass pressure gas therethroughto said contact elements.

8. In a gas pressure operated circuit breaker system; a pair of circuitbreakers; each said circuit breaker including a pair of contactelements, one of said elements being hollow, means supporting saidcontact elements for movement of one relative to the other under theaction of gas pressure to open a circuit therebetween, a pair ofconcentric casings of insulating material constituting arc blo-wingchambers, the bottoms of said casings being open and disposed adjacentsaid hollow 'contact element, an arc-receiving electrode connected to atleast one of said contact elements, said electrode being extended intoone of said casings, and a plurality of metal pins in the wall of eachsaid casing, said pins being disposed one above the other and projectingthrough the walls of said casings at the same levels to form sets ofauxiliary arc-electrodes; connections between corresponding pins in theouter casings of said breakers; means connecting the contact elements ofsaid breakers in series; and means for actuating the contact elements ofboth said breakers simultaneously,

ERNST EICHENBERGER.

REFERENCE S CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 20,044 Clerc July 28, 19361,959,183 Uebermuth May 15, 1934 2,240,233 Thommen Apr. 29, 19412,306,186 Rankin Dec. 22, 1942

